RU2380603C1 - Method for connecting multi-layer composite tubes and device for method's implementation - Google Patents

Abstract

FIELD: construction industry.

SUBSTANCE: method for connecting multi-layer composite tubes is characterised by the fact that multi-layer composite tubes are connected through fittings by means of welding; at that, welding is performed simultaneously along cylindrical and edge surfaces of tube; for this purpose external, internal and edge surfaces and internal surfaces of fitting connected to the tube are pre-heated at one and the same time on end section of tube. Fitting for connecting multi-layer composite tubes is made in the form of coupling with internal fastener with cylindrical socket enveloping internal, edge and external tube surface.

EFFECT: weld formed after the cooling forms reliable joint protected against action of liquid flows.

5 cl, 8 dwg

Description

FIELD OF TECHNOLOGY

The invention relates to the field of joining multilayer composite pipes consisting of five or more layers containing the outer and inner layers of a thermoplastic polymer belonging to the class of polyolefins, adhesive layers and a metal layer, in particular used in cold and hot water supply and heating systems.

BACKGROUND OF THE INVENTION

Known devices for the connection for one-piece tight connection of pipes and methods for the implementation of these connections containing a sleeve (fitting) (RU 2303741, F16L 13/14, 03/03/2003). The specified device does not allow to ensure the reliability of the connection, in particular, due to the possible delamination of the pipes under the dynamic and temperature effects of the liquid.

Closest to the proposed method is a method of welding polymer pipes, which consists in melting the ends of the pipe, heated to or above the melting temperature of the material with a tool (RU 2006144681 A, F16L 13/00, 12/14/2006).

Closest to the proposed device is a coupling for connecting pipes of cold and hot water supply PE-RT of the RUPERT system of the JARUS Nechnik Gmbh company (see Internet link: http://jarus-russia.ru/148.html).

Welding equipment - apparatus for the coupling welding of polymer pipelines O.M.I.S.A. Sri (OMISA) (see the link on the Internet: http://omisa.ru/index/catalogue/showitem.php?id=332).

The specified method and device are characterized by the simplicity of the connection of polymer pipes, but do not provide reliability of the connection of multilayer composite pipes during their long-term operation under the influence of dynamic and thermal loads of liquids.

The objective of the invention is to increase the reliability of the connection of multilayer composite pipes and increase their service life.

SUMMARY OF THE INVENTION

The problem is solved in that in the method the multilayer composite pipes are connected through fittings by welding, while welding is performed simultaneously on the cylindrical and end surfaces of the pipe, for this the external, internal and end surfaces are preliminarily melted at the end of the pipe and the internal surfaces connected to the pipe fitting.

In this case, the preliminary melting of the fitting elements and pipes is carried out along their joined surfaces, that is, without violating the internal structure of the multilayer composite pipe.

And also the task is solved in that the device for implementing the method - the fitting for connecting the multilayer composite pipes is made in the form of a sleeve with an internal fastener with a cylindrical socket covering the inner, end, and outer surface of the pipe.

Moreover, the fitting is characterized in that its internal fastening element is made in the longitudinal axial section of the T-shaped fitting.

Moreover, the fitting is also characterized in that the aspect ratio of the annular protrusion of the inner fastener and the depth of the cylindrical socket of the inner fastener are in the ratio calculated by the formula:

(0.01 to 1) a / G;

Where

“A” is the depth of the annular protrusion of the inner fastener along the longitudinal axis of the fitting;

"G" is the depth of the cylindrical socket of the internal fastener.

In this case, the width of the cylindrical socket of the inner mounting element of the fitting is equal to or less than the thickness of the pipe wall.

Moreover, the fitting is characterized in that it is made of the same polymeric material as the outer and inner layers of the polymer multilayer composite pipe.

Welding of the fitting and the multilayer composite pipe is carried out by preliminary melting the outer, end, and inner surface of the pipe and the surface of the protective fitting seat of the fitting, and then cooling them under natural conditions in the connected state using special welding elements.

The proposed method and device are designed to connect one or more segments of multilayer composite pipes.

The weld formed after cooling creates a reliable joint, protected from the dynamic and temperature effects of fluid flows.

Thus, the specified implementation of the claimed method and device can improve the reliability of the connection of multilayer composite pipes, and also prevent their destruction from delamination under the influence of dynamic and thermal loads of the liquid during operation.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a cross section of a multilayer composite pipe;

figure 2 illustrates the connection of polymer pipes according to the prototype;

figure 3 illustrates the connection of multilayer composite pipes

according to the prototype; figure 4 shows the connection of the multilayer composite pipes according to the claimed method and device,

figure 5 shows a fitting for connecting multilayer composite pipes according to the claimed device;

figure 6 shows an element of a welding device for melting the connected surfaces of the cylindrical socket of the inner mounting element of the claimed device;

7 shows an element of a welding device for melting the surfaces of the final section of a multilayer composite pipe according to the claimed method and device.

EXAMPLE FOR CARRYING OUT THE INVENTION As shown in FIG. 4; 5, the claimed device is a fitting for connecting multilayer composite pipes contains a sleeve 1 with an internal fastener with a cylindrical socket 2, covering the inner, end, and outer surface 3 of the pipe 4.

The inner mounting element of the fitting (figure 5) is made of a "T" -shaped shape.

The ratio of the dimensions of the depth of the annular protrusion of the inner fastener and the depth of the cylindrical socket of the inner fastener (figure 5) are in the ratio calculated by the formula:

(0.01 to 1) a / G;

Where:

“A” is the depth of the annular protrusion of the inner fastener along the longitudinal axis of the fitting;

"G" is the depth of the cylindrical socket of the internal fastener.

Moreover, to ensure reliable tight and uniform contact of the welded surfaces of the fitting and the multilayer composite pipe, the width of the cylindrical socket of the inner mounting element of the fitting is equal to or less than the thickness of the pipe wall.

The element of the welding device 5 (Fig.6) for melting the surface of the cylindrical socket of the inner mounting element of the fitting and the element of the welding device 6 (Fig.7) for melting the surfaces of the final section of the multilayer composite pipe for ease of use can be mounted on one board 7 (Fig.8) .

A device for implementing the inventive method - fitting works as follows.

Multilayer composite pipes 4 are connected through fittings 1 by welding, while welding is performed simultaneously on the end and external and internal cylindrical surfaces of the pipe, for this, the external, internal and end surfaces are pre-melted at the end of the pipe and the internal surfaces of the fitting connected to the pipe.

In this case, the preliminary melting of the fitting elements and pipes is carried out along their joined surfaces, that is, without violating the internal structure of the multilayer composite pipe.

It will be apparent to one skilled in the art that various modifications and changes are possible in the present invention. Accordingly, it is intended that the present invention covers the modifications and variations as well as their equivalents without departing from the spirit and scope of the invention disclosed in the appended claims.

Claims (6)

1. The method of joining multilayer composite pipes, characterized in that the multilayer composite pipes are connected through fittings by welding, while welding is performed simultaneously on the cylindrical and end surfaces of the pipe, for this, the external, internal and end surfaces are pre-melted at the end of the pipe and connected with pipe inner surfaces of fitting. 2. A fitting for connecting multilayer composite pipes, characterized in that it is made in the form of a coupling with an internal fastener with a cylindrical socket covering the inner, end and outer surfaces of the pipe. 3. The fitting according to claim 2, characterized in that its internal fastening element is made in the longitudinal axial section of the fitting "T" -shaped. 4. The fitting according to claim 2 or 3, characterized in that the ratio of the dimensions of the depth of the annular protrusion of the inner fastener to the depth of the cylindrical socket of the inner fastener is (from 0.01 to 1) a / G,
where "a" is the depth of the annular protrusion of the inner mounting element along the longitudinal axis of the fitting;
"G" is the depth of the cylindrical socket of the internal fastener. 5. The fitting according to claim 2 or 3, characterized in that it is made of the same polymer material as the outer and inner layers of the composite multilayer pipe. 6. The fitting according to claim 4, characterized in that it is made of the same polymer material as the outer and inner layers of the composite multilayer pipe.

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